POSSIBLE TWO ELECTRONIC STATES OF Mn ATOMS IN BCC Cr-Mn ALLOYS

1993 ◽  
Vol 07 (01n03) ◽  
pp. 891-894
Author(s):  
M. SHIGA ◽  
H. WADA
Keyword(s):  
Electrical Resistivity ◽  
Thermal Expansion ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Electronic States ◽  
Local Environment ◽  
Negative Temperature ◽  
Environment Effect ◽  
Proposed Model

The thermal expansion, the electrical resistivity and the specific heat of Mn-rich bcc Cr-Mn alloys have been measured. Distinct negative temperature dependence was observed in the thermal expansion and the resistivity at low temperatures. These anomalies are successfully explained on the basis of the two electronic state model by taking account of a local environment effect. An enhanced specific heat at low temperatures is consistently understood in terms of the proposed model.

Electrical Resistivity of an Al-Re-Si Cubic Approximant Phase and Role of Local Environment in Electronic Transport

2000 ◽  
Vol 643 ◽  
Author(s):  
Ryuji Tamura ◽  
Takayuki Asao ◽  
Mutsuhiro Tamura ◽  
Shin Takeuchi
Keyword(s):  
Electrical Resistivity ◽  
Electronic Transport ◽  
Electronic States ◽  
Local Environment ◽  
Negative Temperature ◽  
Icosahedral Phase ◽  
High Resistivity ◽  
Icosahedral Quasicrystal ◽  
Icosahedral Phases

AbstractIn order to gain an insight into the role of the local atomic environment in the electronic transport of the icosahedral quasicrystal, the electrical resistivity of α-AlReSi, which is the (1/1,1/1,1/1) approximant of the icosahedral phase, has been investigated. Very high resistivity and its pronounced negative temperature dependence have been observed, indicating that the electronic states of the 1/1 cubic approximant are quite similar to those of icosahedral phases. In order to further elucidate which structural entity is responsible for such anomalous transport, a comparison of the electrical resistivity between (1/1,1/1,1/1) and (1/0,1/0,1/0) approximants has been made. The typical transport behavior of icosahedral phases which is also seen in 1/1 and higher-order approximants was not observed in any of the studied 1/0 cubic approximants. The result can be regarded as an implication that the intercluster distance between the TM clusters plays a significant role in the confinement of electronic states.

TEMPERATURE DEPENDENCE BEHAVIOR OF ELECTRICAL RESISTIVITY IN NOBLE METALS AT LOW TEMPERATURES

2014 ◽  
Vol 5 (3) ◽  
pp. 982-992 ◽  
Author(s):  
M AL-Jalali
Keyword(s):  
Experimental Data ◽  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Concentration Dependence ◽  
Low Temperatures ◽  
Noble Metals ◽  
Phonon Scattering ◽  
Theoretical Models ◽  
Residual Resistivity ◽  
Electron Phonon Scattering

Resistivity temperature – dependence and residual resistivity concentration-dependence in pure noble metals(Cu, Ag, Au) have been studied at low temperatures. Dominations of electron – dislocation and impurity, electron-electron, and electron-phonon scattering were analyzed, contribution of these mechanisms to resistivity were discussed, taking into consideration existing theoretical models and available experimental data, where some new results and ideas were investigated.

Negative temperature dependence of electrical resistivity in TiNi alloys

1997 ◽  
Vol 237-238 ◽  
pp. 609-611 ◽  
Author(s):  
T. Fukuda ◽  
T. Kakeshita ◽  
T. Saburi ◽  
K. Kindo ◽  
T. Takeuchi ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Negative Temperature ◽  
Ni Alloys

Electronic properties of the actinide metals at low temperatures

1963 ◽  
Vol 276 (1367) ◽  
pp. 553-570 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Low Temperatures ◽  
Negative Temperature Coefficient ◽  
Negative Temperature ◽  
Al Alloys ◽  
Positive Temperature ◽  
Positive Coefficient ◽  
Disorder Effects ◽  
Temperature Coefficients ◽  
Spin Disorder

The electrical resistivity and thermoelectric power of thorium, uranium, neptunium and plutonium have been measured down to liquid-helium and liquid-hydrogen temperatures. The resistivities are relatively high, especially those of neptunium and plutonium, while all the thermoelectric powers show complicated temperature relations. The temperature dependence of the resistance of a-plutonium is abnormal, being characterized by a small negative temperature coefficient above 105 °K and a large positive coefficient below this temperature. Some plutonium rich d-Pu + Al alloys also show similar behaviour. An explanation in terms of spin-disorder effects seems most reasonable, and it is suggested that both a- and d-plutonium may be antiferromagnetic. The resistance—temperature curves of uranium and neptunium also are unusual in that the positive temperature coefficients decrease monotonically with rising temperature. Possible reasons for this have been discussed.

ROLE OF FRUSTRATION IN MAGNETISM AND THERMODYNAMIC PROPERTIES OF YMn2 AND β-Mn

1993 ◽  
Vol 07 (01n03) ◽  
pp. 1008-1012 ◽  
Author(s):  
M. SHIGA ◽  
K. YOSHIMOTO ◽  
H. NAKAMURA ◽  
H. WADA
Keyword(s):  
Electrical Resistivity ◽  
Magnetic Susceptibility ◽  
Thermodynamic Properties ◽  
Specific Heat ◽  
Temperature Dependence ◽  
Ground State ◽  
Quantum Spin ◽  
Spin Liquid ◽  
Quantum Spin Liquid

The temperature dependence of the magnetic susceptibility, the specific heat and the electrical resistivity of Y(Sc) (Mn1−xAlx)2 and β-Mn1−xAlx systems has been measured. It is shown that the ground state for x=0 is not a simple Pauli paramagnet but may be regarded as a quantum spin liquid. The substitution of Al for Mn results in the spin glass freezing. The role of frustration is discussed for understanding these phenomena.

Temperature dependence of the electrical resistivity of copper at low temperatures

1977 ◽  
Vol 55 (23) ◽  
pp. 2071-2079 ◽  
Author(s):  
P. K. Moussouros ◽  
J. F. Kos
Keyword(s):  
Electrical Resistivity ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
Pure Copper ◽  
Impurity Effects ◽  
One Step

Precise measurements of the electrical resistivity of pure copper samples have disclosed two discontinuities in the temperature dependence of the resistivity. They occur at approximately 6.7 K and near 12.1 K. The second is associated with impurity effects whereas the first appears to be a characteristic of the metal itself. It is similar to the discontinuity previously observed in the temperature dependence of the electrical resistivity of Ag by Kos and independently by Ehrlich and Schriempf and attributed by the former to one-step umklapp processes.

Electrical resistivity of gallium single crystals at low temperatures

1951 ◽  
Vol 209 (1099) ◽  
pp. 542-550 ◽  
Keyword(s):  
Electrical Resistivity ◽  
Specific Heat ◽  
Single Crystals ◽  
Low Temperatures ◽  
Room Temperature ◽  
Resistivity Measurements ◽  
Characteristic Temperatures ◽  
The Ideal

Electrical resistivity measurements on single crystals of gallium grown to conform approximately to the three axial directions have been extended to low temperatures, detailed investigation being made over the range 20.4 to 4.2° K. The anisotropy of this property increases in this region where the resistivity ratios for the three specimens are approximately 1: 2.1: 8 compared with 1: 2.1 6 : 6.5 5 at room temperature. The ‘ideal’ resistivity is proportional to T n , where n ≃ 4.45 for the range 5 to 12° K and decreases to about 3.9 for the range 12 to 20.4° K. The characteristic temperatures as derived from Grüneisen’s expression show relatively small differences for the three axial directions but decrease with decrease in temperature. Comparable variations with temperature are observed in the characteristic temperatures derived previously from specific heat measurements on gallium.

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